CVE-2023-26491 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in rsshub. A fix is available for rsshub — see the affected versions and patch details below.
RSSHub is vulnerable to cross-site scripting (XSS) via unvalidated URL parameters
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-26491.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-26491 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
rsshubnpmDescription
RSSHub is an open source and extensible RSS feed generator. When the URL parameters contain certain special characters, it returns an error page that does not properly handle XSS vulnerabilities, allowing for the execution of arbitrary JavaScript code. Users who access the deliberately constructed URL are affected. This vulnerability was fixed in version c910c4d28717fb860fbe064736641f379fab2c91. Please upgrade to this or a later version, there are no known workarounds.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | rsshub | all versions | 1.0.0-master.c910c4dnpm install rsshub@1.0.0-master.c910c4d |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rsshub, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rsshub to 1.0.0-master.c910c4d or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26491 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-26491 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-26491. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-26491 in your dependencies?
O3 Security finds CVE-2023-26491 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.